Doogie and Tom venture back into space—because it went so well in 'Aliens'. 
Fewer xenomorphs this time, but still plenty of hazards to negotiate including flying space debris, exploding airlocks and George Clooney's terrible jokes. Luckily, they've brought a real-life astronaut along for the ride. Professor Greg Chamitoff is here to hold their gloves as they try not to die in zero gravity (7.18), and answer some bonus questions about important things like whether he ever saw a real live ET up there (23.42).